#include<bits/stdc++.h>
using namespace std;
const int N=5005;
typedef long long ll;
vector<int>e[N];
int n,s,a[N],w[N],p[N],rg[N],cr,c[N];
ll f[N][N],ans,sum;
bool vis[N];
void dfs(int x){
	for(int i=1;i<=n;++i)f[x][i]=-1ll*p[x]*i+(i&1)*w[x];
	for(auto v:e[x])if(!vis[v]){
		dfs(v);
		ll mx=0;
		for(int j=1;j<=n;++j){
			mx=max(mx,f[v][j]);
			f[x][j]+=mx;
		}
	}
}
int main(){
	scanf("%d%d",&n,&s);
	for(int i=1;i<=n;++i)scanf("%d",&w[i]);
	for(int i=1;i<=n;++i)scanf("%d",&p[i]);
	for(int i=1;i<=n;++i){
		scanf("%d",&a[i]);
		e[a[i]].push_back(i);
	}
	for(int i=s;!vis[i];i=a[i])vis[i]=true,rg[++cr]=i;
	for(int i=1;i<=cr;++i)dfs(rg[i]);
	for(int i=1;;--i){
		if(!i)i=cr;
		int x=rg[i];
		sum-=f[x][c[x]];
		++c[x];
		if(c[x]>n)break;
		sum+=f[x][c[x]];
		ans=max(ans,sum+p[s]);
	}
	printf("%lld\n",ans);
	return 0;
}